Drtryder

Hi i need help i have a 93 camaro z28 with the 5.7 with the 383 stroker kit 6 speed car runs great until hot then start backfiring threw exhaust an intake when I accelerate i changed the optispark o2 sensors plugs wires icm tested about everything plugged into computer throwing code 16 whats my issue ??? Car mods are Heads are port and polished beehive springs .575 lift cam has center force dual friction clutch. Aluminum fidanza flywheel aluminum deiveshaft headers 42 lb injectors afpr port and polish intake. 4.10 gears transmission was new at 56k miles brand new. The stroker is a kit from eagle all eagle esp internals balanced and block was clearanced. H beam rods. Arp everything. msd 6al box

Injuneer

"New Member Intro" isn't the best place for tech help. I'll move this to "LT1 Based Engine Tech" to improve your chances of a response.

Drtryder

Sorry not to sure how to use site yet thanks

Injuneer

Did this problem exist BEFORE you installed the new Opti? What brand Opti did you install?

DTC 16 indicates loss of low resolution pulse signal from the optical cam position sensor in the Opti. If it runs, the code is stored and not active, since an active code shuts down the fuel system. It should also be noted that DTC 16 does not turn on the SES light.

Erratic timing could be due to a faulty signal from the high resolution signal in the cam position sensor. When you installed the new Opti, did you check the harness connectors for corroded or damaged pins, or damaged wire insulation? Heat soak can affect the cam position sensor module, and it is a bigger problem with cheap Optis with Chinese modules in them, but I have seen the problem from the MSD units.

Drtryder

I used a summit brand opti i changed all the seals the harness looked good to me i chased it to the ecm and im getting good readings from it the car only does this when its at running temp its starts mising and back firing under load do you think i got a bad opti or is my trouble else were the code we got was a 16 low impulse like i said ive changed everything and this problem was here before i changed opti but the water pump was leaking on the old one so i changed it figured that was my issue but with new seals an new opti still doing it but before the car would die completely when hot and not restart until it sat for 10 15 mins

Injuneer

When you had the ICM tested, did they test if repeatedly to get it good and hot?

Drtryder

Yes i replaced it 3 times now everytime i take it off take it back in it says its bad what would cause it to keep goin bad i did the cooling mod on it would my msd box be burning them up

Injuneer

Clear the code and see how fast it comes back.

Drtryder

Only code im gettin is 16 but soons as i clear it comes right back instantly

Injuneer

When you are trying to start the engine?

Would indicate failure of the cam position sensor module in the Opti, or a bad wire from the PCM to the Opti.

Wiring diagram, courtesy of Shoebox:

http://shbox.com/1/93_ign_system_schematic.jpg

Drtryder

Well i just orderd another opti and a coil an icm and the harness for opti do you think that opti would fail only when hot tho